On Wed, May 05, 2021 at 02:04:44PM -0700, Boris Burkov wrote:
> generic/574 has tests for corrupting the merkle tree data stored by the
> filesystem. Since btrfs uses a different scheme for storing this data,
> the existing logic for corrupting it doesn't work out of the box. Adapt
> it to properly corrupt btrfs merkle items.
>
> This test relies on the btrfs implementation of fsverity in the patches
> titled:
> btrfs: initial fsverity support
> btrfs: check verity for reads of inline extents and holes
> btrfs: fallback to buffered io for verity files
>
> A fix for fiemap in the patch titled:
> btrfs: return whole extents in fiemap
>
> and on btrfs-corrupt-block for corruption in the patches titled:
> btrfs-progs: corrupt generic item data with btrfs-corrupt-block
> btrfs-progs: expand corrupt_file_extent in btrfs-corrupt-block
>
> Signed-off-by: Boris Burkov <boris@xxxxxx>
> ---
> common/verity | 18 ++++++++++++++++++
> tests/generic/574 | 5 +++++
> 2 files changed, 23 insertions(+)
>
> diff --git a/common/verity b/common/verity
> index d2c1ea24..1636e88b 100644
> --- a/common/verity
> +++ b/common/verity
> @@ -315,6 +315,24 @@ _fsv_scratch_corrupt_merkle_tree()
> (( offset += ($(_get_filesize $file) + 65535) & ~65535 ))
> _fsv_scratch_corrupt_bytes $file $offset
> ;;
> + btrfs)
> + local ino=$(stat -c '%i' $file)
> + _scratch_unmount
> + local byte=""
> + while read -n 1 byte; do
> + if [ -z $byte ]; then
> + break
> + fi
> + local ascii=$(printf "%d" "'$byte'")
> + # This command will find a Merkle tree item for the inode (-I $ino,37,0)
> + # in the default filesystem tree (-r 5) and corrupt one byte (-b 1) at
> + # $offset (-o $offset) with the ascii representation of the byte we read
> + # (-v $ascii)
> + $BTRFS_CORRUPT_BLOCK_PROG -r 5 -I $ino,37,0 -v $ascii -o $offset -b 1 $SCRATCH_DEV
> + (( offset += 1 ))
> + done
> + _scratch_mount
> + ;;
> *)
> _fail "_fsv_scratch_corrupt_merkle_tree() unimplemented on $FSTYP"
> ;;
> diff --git a/tests/generic/574 b/tests/generic/574
> index 1e296618..e4370dae 100755
> --- a/tests/generic/574
> +++ b/tests/generic/574
> @@ -43,6 +43,11 @@ _scratch_mount
> fsv_orig_file=$SCRATCH_MNT/file
> fsv_file=$SCRATCH_MNT/file.fsv
>
> +# utility needed for corrupting Merkle data itself in btrfs
> +if [ $FSTYP == "btrfs" ]; then
> + _require_command "$BTRFS_CORRUPT_BLOCK_PROG" btrfs_corrupt_block
> +fi
I don't think this is needed, as _require_scratch_verity() already did
this check.
Thanks,
Eryu
> +
> setup_zeroed_file()
> {
> local len=$1
> --
> 2.30.2
